To place the Large Wood Box you must move the item to your hotbar and then move your mouse around until the red box becomes blue (Indicating that it can be placed). After placing the box, you can add a Code Lock to increase security. To use the box and see the contents inside, as well as being able to take items out/ put them in, align the cursor to the box and press the Use button (default "E").

If a code lock is attached, intruders will have to destroy the box to gain access to its contents. Some items (8-15 slots) will be lost upon destroying it.The box can be destroyed with approximately 18 hits from a Pick Axe.